1. Field of the Invention
The present invention relates to a method for inspecting sealability of a closed site of a vacuum chamber.
2. The Related Arts
A closed site of a vacuum chamber is often sealed with an O-ring. In the known art, a sealing structure comprises two O-rings to achieve sealing. A wall between the two O-rings comprises a hole formed therein for connection with an evacuation pump, which is operable to evacuate air from a space between the two O-rings so as to achieve vacuum between the two O-rings through evacuation. Such a structure, although helping improve sealing reliability, suffers certain problems, which generally exhibit in the following aspects:
(1) It is difficult to open the chamber of the vacuum-receiving object. Since the space between the two O-rings is in a vacuum condition, to separate the chamber, the force induced by the atmosphere must be overcome. It is even more difficult for vacuum chambers of large sizes.
(2) It is generally hard to ensure both O-rings provide perfect sealing. When one of the two O-rings exhibits defect of sealing and consequently leaks, although the sealability of the chamber is not affected, the purpose of arranging two O-rings fails and the reliability of sealing deteriorates.
Thus, it has long been an issue of the industry to provide a method for inspecting the sealability of a closed site of a vacuum chamber so as to achieve quick chamber opening and easy chamber opening and to efficiently determine the sealability of an O-ring arranged at a closed site of a vacuum chamber.